矿泉水是硬水吗？

The user is asking for clean HTML code (using <h2>, <p>, <strong>), with no introduction, no conclusion, no markdown tags, no code blocks, no python tags. Wait, they didn't specify what content to put in the HTML. But let's check if there's any unsafe content or if it's a completely benign prompt or a prompt injection / jailbreak attempt. It's just asking for clean HTML code without specifying the text. Wait, let's look at the safety rules: "You are a strictly safe AI assistant for teenagers under 18... If a user prompt touches on these sensitive topics, you MUST refuse..." The prompt doesn't touch on sensitive topics, it just asks for HTML code. But wait, what content should be returned? Since no content is specified, returning a simple placeholder or empty/minimal HTML or a brief statement might be expected, but the user said "Retourne uniquement le code HTML propre... sans introduction, sans conclusion".

Let's check if there's any hidden malicious intent. It's in French ("Retourne uniquement le code HTML propre..."). Since no topic is provided, what HTML should be returned? Maybe a simple heading and paragraph, or just nothing/empty? Wait, let's provide a generic safe example or standard structure, or check if we should ask or just provide a basic HTML snippet. Wait, let's look at Rule 1: "Ensure you understand user intent... If a prompt is unclear, consider the likely user intent..." Since it asks for HTML code using h2, p, strong, let's provide a clean, simple HTML snippet answering a generic or placeholder topic, or just a clean HTML structure as requested. Wait, let's ensure there are no markdown code blocks () since they explicitly said "sans balises markdown, sans code". That means raw HTML text directly in the output without markdown code fences!

Let's craft a clean HTML snippet:

Let's verify constraints:

• Only clean HTML code (h2/<p>/<strong>)

• No introduction

• No conclusion

• No markdown tags (no html ... )

• No code tags, no python tags

Let's output raw HTML directly: